In this talk, I will be focusing on our recent advancement in the field of SERS as an ultrasensitive and molecular specific bio-sensing platform, specifically for the detection of various biomarkers and in the development of bio-assays. SERS detection relies on the giant amplification of the vibrational ‘fingerprint’ of the Raman scatter signal when the analyte is in a close proximity to nano-roughened silver or gold coated substrates/colloids. SERS biosensor platforms are developed using novel nanomaterial concepts integrated with substrates or optical fiber platforms. In vivo biomarker detection in animal model using SERS-active nanoparticles will also be discussed.